The present invention relates generally to optical lenses, and more particularly to lens actuation assemblies.
Current lens systems (e.g., for camcorders, closed circuit television cameras, etc.) typically employ a rotational means of positioning lens elements. In one common method, the rotational motion is generated by a small motor that drives a lead screw mechanism, which in turn linearly drives the attached lens elements. In another common method the entire lens assembly is moved by means of a screw action similar to that of manually adjustable camera lens. In both cases, the motor must drive at excessive angular velocity to achieve desirable zoom or focus lens performance due to the fine thread pitch of either the lens barrel external thread or the lead screw. Using this type of conventional lens positioning technology allows for lens target acquisition times in the order of one second.